Anybody wanna take a guess on my 8BA overheating situation

It sounds like you are adding water pretty regularly. If it is not in the oil or leaking out of the radiator or block somewhere it has to be draining out of the overflow. Maybe the engine is not letting water flow very well, the water expands in the radiator and has to go out the overflow until it is low on water and the temp starts to rise. Maybe there is a restriction on one side of the engine or pump?

 

Thanks for the replies so far. Im still at work so Im not able to actually do anything suggested so far. I would like to rule out head gasket and I dont know but I just think it somehow is caused by a coolant flow problem or restriction maybe an airlock developing somehow.
Here is the kicker might be just a coincidence maybe not this all started recently after I changed out Rear ends from the stock 3.73to a 3.50 for better highway driving.

 

lowered the rpms as a result...check your timing...may be just a bit too advanced at those rpms.

 

Im actually running about the same RPMs just a few MPH more than before

 

Mike,

Here's another off the wall suggestion for you. How's your oil level? Low oil will also cause the water temp to rise. On my Olds, If it gets down a quart, the water temp will rise. Going down the road it will have some of the symptoms you're facing. But in the driveway, or just puttering along, I seem to be ok. But if I try to go freeway speeds, then I too notice it will rise to higher than normal.

Too, like a flathead, I don't have the puke can, just the over flow tube. I only notice mine being hot from the single water temp gauge, and if it is hotter than normal, when I stop, water will come out the over flow tube, telling me that it was running hotter than normal.

I'd really have to dig thru some of my old flathead stuff, but isn't a stock radiator cap for the flathead 4 lbs instead of 7?

Also, does it cool down any when you slow down? As you mentioned, going faster at highway speeds, should increase the airflow, going at the same RPMs. But taking some of the "load" off of the engine. What does it do, if you try and drive as long as you can just in second gear, and keep the RPM's at about what you would get at highway speeds???? Providing you have a stretch of road that you can drive for a little while in second gear.


HellRaiser

 

Hey Dallas, fresh oil and full,
Its never really overheated while driving in town just when cruising at a steady speed about 55 MPH or so but once it starts to get hot it will rapidly progress and once it gets to 210 even slowing down then wont cool it off.B ut if you stop for even 5 mins top it off which usually only takes about 1/2 gallon or less you can start it back down the road it will run 190 or so again for a good while.

 

Hate to show my ignorance, but can these engines suck the radiator hoses flat after they warm up?

 

Try advancing the ignition a bit.

 

UPDATE: finally got time to tinker with it today I think (crossed fingers) I found it. I went ahead and pulled the radiator out again today (I had it boiled out at a radiator shop once already) anyway I took it to the radiator shop he was going to flow test it for me when I picked it up I turned it upside down and shook it and it sounded like a can of bolts inside the top tank so it seems that as I drive it at higher speeds the big rust balls are coming loose and passing thru the upper hoses into the top tank and settling in and on top of the tubes after a while causing enough restriction to make it overheat.
So now how do I get the big rust balls and flakes cleaned out of the block/heads? I think I'm going to put some type of screen or something in my upper hoses to catch it, but other than flushing the heck out of it anybody have any ideas for cleaning the rust scale out of the block?
Oh and Thanks again for all the replies!!!

 

Other than flushing the block with commercial flushing solutions, there is no sure fire way to remove rust with the engine assembled in the car. Have your radiator cleaned, flush the motor, and drive the car. Test for combustion gasses in your coolant after the car has a few hundred miles on it. You may still have a blown head gasket or a crack somewhere causing a loss of coolant through the exhaust. Your sudden increase in temp is an indication that you are loosing coolant while you are driving.

 

The screen idea should work. I have been told a nylon stocking in the top radiator hose going into the tank for catching rust and stuff.

Neal

 

So I tried the Nylon stocking trick in both upper hoses. I took the car on a 320 mile round trip. ( I also removed both thermostats so to eliminate any restrictions in flow) The first 160 miles it never got over 180. On the return trip after about 50 miles it started to gradually increase to the point that my last 20 miles were at about 205* after it cooled I pulled the nylon stockings out to see if any debris had been trapped and this is what I found.

 

I'm going with Neal on this one, gasket or cracked head. The water you are adding is going somewhere.

 

I should have stated in my previous post that after the first leg of the trip the radiator was still full.
I think the handfull of rust confirms the problem. On the return trip the temp started to gradually increase from the stockings beginning to get clogged up from all the crap they were trapping. Besides the bigger stuff that I showed in the picture they the stockings were clogged with a very fine layer of stuff that I had to wash out of them after turning them inside out.

 

Russco, seems like you solved your problem. Great! The loose rust seems to make sense considering the intermittent nature of the problem. Thanks for the feedback on what you tried and what worked. How about posting an explanation of how you used nylons as filters in the upper hoses. Did you stretch them tight, leave them loose like a sock, wad them up, or what? Did you put them on the heads or at the radiator? Filtering the coolant is a good, easy technique to troubleshoot/resolve an overheating problem.

 

You had the radiator boiled out. Did he remove the tanks and rod out the tubes also? I had the same problem, 8ba in a '35 and it pressure checked to 12 lbs, still overheating on trips. Rodded it out and no problems.
Hope getting the grit out helped.
RB

 

Thanks for posting the solution it may help a lot of us in the future.

 

Buy your wife or girlfriend a new pair of nylons and tell her thanks !!!!!!!!!!!!

 

I didnt read all these posts but I would check the cap-

You should have a 4 pound cap and nothing higher- I bought a shoebox that did the same thing yours did and the only thing that was wrong was that the guy put a 12 pound cap on it- this is a non pressurized system- and the water level should be a few inches down from the cap- not FULL

 

Another update: Its still running hotter than it used to. its not really overheating per say but its running over 200-210 it always used to run 180 or so today just as I got home from a 20 mile drive and the temp was reading about 205 I turned the garden hose on and sprayed the lower half of the rad with the car idling. to me this should have drastically lowered the temp but it didnt which leads me to think the radiator flow is stil somewhat restricted. I know the radiator has been boiled out 3 times now and he says it flow checks ok but I think maybe it needs rodded out as mentioned above. Any other thought or ideas?

BTW Tuck I have tried 2 new caps with no change (4 PSI and 7 PSI)

 

You need a radiator

 

I had the simular problem with a 7* rad cap it was a short neck cap and the coolant was puking out the overflow tube....The 8BA rad uses a 4* cap with a long neck. The coolant should be about an inch below the top of the tank. If you fill it right up it will siphion it out through the over flow tube.
Jim